The present invention relates to an improved driving assurance system.
Systems utilizing the absence of a constant slight oscillatory movement of the steering wheel of an automotive vehicle to operate a warning signal are well known in the art. The prior art systems usually employ an arcuate light shield having a series of apertures arranged at a predetermined angular spacing. The shield is mounted on the steering wheel of a vehicle for rotation therewith. A light source and a photoelectric cell are stationarily mounted in opposed relation with the light shield therebetween so that by rotation of the steering wheel a number of electrical pulses will be generated in response to the passing and intercepting of the light by the light shield. However, the arcuate extent of steering movement varies widely depending upon the driver's steering behavior, the vehicle's driving performance and the roadway conditions. Therefore, a larger number of pulses will be generated by a single steering operation when such operation exceeds an arcuate extent much greater than the spacing between successive ones of the apertures of the light shield, and thus does not accurately represent the actual steering operation.